A model for Dirac neutrino masses and mixings

Abstract

We present a gauge model for three families of fermions, where the Dirac neutrino mass matrix is calculable and takes a particularly simple form. The model predicts m ν e ≈ 0 and m ν μ , m ν τ ≠ 0. Using known constraints on the mixing of the electron neutrino, we further predict that m ν μ / m ν τ ≈ m τ /2 m e . When combined with cosmological constraints on the mass density of the universe, this leads to m ν τ < 10 −2 eV, which is in the correct range to provide a solar neutrino puzzle via MSW oscillation effect between ν e and ν τ.